Journal of Metals, Materials and Minerals, Vol.26 No.2 pp.21-26, 2016

Ballistic Resistance of Plain Woven p- Fabrics

Somchai UDON1, Manoon JITJAICHAM2 and Boonsri KUSUKTHAM1*

1*Division of Textile Chemical Engineering, Faculty of Textile Industries, Rajamangala University of Technology Krungthep, Bangkok 10120, 2Division of Textile Engineering, Faculty of Textile Industries, Rajamangala University of Technology Krungthep, Bangkok 10120, Thailand

Abstract

This research investigated the ballistic resistance of p-Aramid fabric. Plain woven aramid fabrics were prepared to produce bulletproof vest having 5 kg of 32 fabric layers. The of the multilayer aramid fabrics in terms of ballistic resistance was evaluated by ballistic testing with the difference types of . The damage of the fabric and the indentation of modeling clay behind the target were examined. The results showed that vests prepared from 18 - 32 fabric layers exhibited the ballistic resistance; the more the fabric layer the more the resistance performance. In addition, the indentation of the modeling clay decreased drastically from 150.2 mm to 23.5 mm. The resistance performance was found dependent on layers of the fabric and bullet type.

Key word: Aramid fabric, Bulletproof vest, Bullet impact, Plain weave Various materials have been employed Introduction for the protection against the ballistics such as (5) (6) (4) composite. , steel. , . and Bulletproof vest is a protective clothing synthetic fibres.(3, 7-9). The synthetic fibres which which protects the . In designing the use for ballistic protection are ultra high bulletproof vest, types of material such as fibres molecular weight polyethylene and aramid fibres. and performance of protection will be considered. Type of ballistic protection clothing could be Para- are fibres of very high (1) divided into soft and hard armour. The orientation and high strength.(10) It was used in soft armour is made from textile material safety and protective clothing such as body amour protecting the wearer from small-caliber due to good dynamic energy absorption and shotgun. In contrast with the soft armour, the characteristics, high strength and modulus, and hard armour consists of vest reinforced with excellent thermal properties.(1) hard-plate such as metal or ceramic for protecting

other weapons. The performance of the bulletproof vest,

made from textile fabrics, depended on the inner From the National Institute of Justic (2) factor of the bulletproof vest such as fibre type, Standard. , the ballistic-resistant body armour is fibre properties, yarn structure and fabric divided into different types. First, for routine construction. Also, the outer factor was condition wear is available in type I, II-A, while type II will of shooting such as type of bullet, velocity and protect from common handgun. Second, type III- size of the bullet.(11) Demeski et al. reported that A will provide protection from 9mm gun and .44 the cross over points of warp and weft yarns of a magnum . Finally, types III and IV will ballistic fabric were the highest damage from the protect against high powered rifles. The working (5) bullet impact. The ballistic impact of the principle of the bulletproof vest made from synthetic fibres was explained in the following.(3-4) woven fabric impregnated with a colloidal silica was studied by Lu et al. The impregnated fabric When the bullet striked the vest, the fibres in the exhibited less pullout of yarns. Also, the vest caught the bullet and brought it to a stop. increasing of the layers of the fabric decreased the These fibres absorbed and dispersed the impact (3) penetration depth of modeling clay. Regassa et energy as heat, causing the bullet to deform. al. reported that the composite body amour of 20

J.Met.Mater.Miner.26 (2) 2016, DOI:10.14456/jmmm.2016.7

Corresponding author E-mail : [email protected]

22 UDON, S. et al

layers of the woven Kevlar-29 fibre with The 32 layers of the aramid fabric were polyester resin showed no penetration of bullet cut to form the bulletproof vest covered with the impact.(9) black polyester fabric. The vest size was shown in Table 1. The fabric construction (plain, twill basket and satin) of the Aramid fabric on the Table 1 Size of bulletproof vest bulletproof behavior was reported by Chu and Measurement Size (cm) Chen. At low speed test of bullets, the single- Chest 112 layer of plain weave construction showed the best Neck size 42 proofing properties. In the hight speed testing, Sleeve 89 multilayer construction of basket fabric had the Waist 97 highest resistance, followed by the plain weave construction. The fabric construction was the Ballistic tests important factor to stop the bullet. The fibres in The woven fabric (18-30 layers) or the the vest should be packed tightly.(11) bulletproof vest (32 layers of the aramid fabric) Hence, it is interesting to study the bullet were impacted with the bullet at distance 5 meter. resistance of textile fabrics. In this study the p- A thick block of modeling clay in wooden mold aramid spun yarns was woven into plain fabric. (15.24 cm × 8.89 cm × 8.89 cm) were placed The ballistic resistance of the aramid fabric was behind the fabric and clamped together with the examined. The ballistic resistance performance elastic tape as shown in Figure 1. For estimation was evaluated based on two factors (bullet of the bullet impact on the target, an indentation type and fabric layers). In this study, up to 32 on the surface of the modeling clay was measured fabric layers were constructed to produce the as shown in Figure 2. bulletproof vest. The bullets used were 9 mm, .357 magnum and .44 magnum.

Materials and Experimental Procedure bullet

Materials

aramid fabric or p-Aramid spun yarns purchased from bulletproof vest Crosstex Co., Ltd (Thailand).

Measurement of tensile properties of yarn

Tensile properties of p-aramid spun yarns were measured according to the ASTM D2101-93 standard test method using an modeling clay

Universal Testing Machine (Hounsfield H10KM, U.S.A.) The cross head speed used was 300 Figure 1 Schematic diagram of the ballistic test. mm/min. 12 samples were used for measurement; using the gauge length 200 mm and the average values were reported. modeling clay

Production of Aramid fabrics The p-aramid spun yarn was weaved to plain woven fabric construction. Figure 2 Schematic diagram of the indentation of modeling clay behind the target after bullet impact. Measurement of weight of aramid fabrics The weight of the aramid fabrics were Results and Discussion measured by using balance. Measurement were Tensile properties of aramid yarns made from the sample, having the size 40×40 cm. The tensile strength and elongation of the

aramid yarns are shown in Table 2. The result Production of bulletproof vest

J.Met.Mater.Miner.26 (2) 2016, DOI:10.14456/jmmm.2016.7

23 Ballistic Resistance of Plain Woven p-Aramid Fabrics

showed that this material had low elongation but weaving into fabric. high strength. Thus, this yarn was suitable for Table 2 Strength and elongation of p-aramid yarn

Properties Value Tensile strength 208.5 N Tensile elongation 35.5 mm

Weaving of the aramid fabric 30 yarns / inch and weft yarn, also, number 10/2 with 30 yarns / inch. The aramid fabric was weaved to plain The weight of the aramid fabric was 550 weave construction. Plain weave is the simple g/m2. The result showed that it had the heigh weave. The weft yarns pass over and under weight. For production of the billetproof vest, it alternative warp yarns. This is the maximum indicated that the used of the aramid fabric caused amount of interlacing possible in a woven fabric. the heavy weight of the vest. This resulted from Thus the fabric is strong and durable. the construction of the fabric. Specification of the aramid fabric is shown below. Ballistic test of aramid fabrics width of fabric warp yarn × weft yarn For testing of the ballistic, the target number of warp yarn × number of weft yarn (aramid fabrics) composed of 18-30 layers of the fabric. The result of the testing are shown in 48 10/2 × 10/2 Table 3 and Figure 3-4. The resistant 30 × 30 characteristic of the aramid fabric from the bullet This data showed that the width of the impact was evaluated from the fabric destruction woven fabric was 48 inch (121.92 cm). This and an indentation of the modeling clay. fabric consisted of warp yarn number 10/2 with

Table 3 Ballistic performance of aramid fabric with the difference layers

Level of NIJ ballistic Type of bullet Layers of Impact velocity Penetration protection fabric (m/s) depth (mm) IIA .357 magnum 18 352 150.2

24 358 23.1 II 9 mm 24 436 32.4 IIIA .44 magnum 24 453 36.1 30 450 31.4 30 452 32.9

a b

J.Met.Mater.Miner.26 (2) 2016, DOI:10.14456/jmmm.2016.7

24 UDON, S. et al

Figure 3 Testing of aramid fabric with .357 magnum: (a) penetration of the bullet at the front of the modeling clay and (b) the thrown off at the back of the modeling clay box. protection, the layers of the fabric should be increased. a The failure of the fabric by the bullet impact was described in the following (1, 7). The absorption of the energy by the fabric was occurred during the bullet impact. Also, the energy was transferred to the yarns. This caused the defect of the fabric after impact by the bullet. For the thick layer of the fabrics, the dissipation of the energy was likely provided by the first layer of the aramid fabrics. This resulted in the indentation of the modeling clay and the stop of the bullet as shown in Figure 4.

Ballistic test of bulletproof vest b For cutting the bulletproof vest, the 32 layers of aramid fabric was used. The vest was designed for realistic testing. The bulletproof vest product with the weight of 5 kg was shown in Figure 5. In general, the bulletproof vest must be light weight. From the National Institute of Justic (NIJ) (U.S Department of Justice) (2), the Kevlar bulletproof vest must have a minimum 4 pound (1.81 kg) in order to give good protection.

Figure 4 Testing of 30 layers of aramid fabric with .44 magnum: (a) stop of the bullet in the Kevlar and (b) indentation of the modeling clay at the back of the aramid fabric.

At the condition of the .357 magnum and 18 layers of the aramid fabric, the bullet passed through the panel (see Figure 3 (a)) and caused the material to be thrown off at the back of the panel as shown in Figure 3 (b). Hence, the 18 layers of the aramid fabric were not sufficient to protect the impact from the bullet. For the same type of the bullet, the result Figure 5 Characteristic of bulletproof vest. showed that the increasing the layers of the aramid fabric increased the resistance of the bullet penetration (see Table 3). Also, the indentation of For testing of the bulletproof vest from the modeling clay decreased. This indicated that the bullet impact, the vest was tested under .44 the performance of the aramid fabric from the magnum at the front size and back size of the impact increased. However, for 24 layers with the vest. The result is shown in Table 4 and Figure 6. different types of the bullet, the increasing the velocity of the bullet increased the indentation of the modeling clay (see Table 3). This resulted from the high energy of the high velocity of the bullet impact. Thus, for increasing the level of

J.Met.Mater.Miner.26 (2) 2016, DOI:10.14456/jmmm.2016.7

25 Ballistic Resistance of Plain Woven p-Aramid Fabrics

Table 4 Ballistic performance of the bulletproof vest produced from aramid fabrics

Position of Panel Times of shooting Impact velocity (m/s) Penetration depth (mm)

Front 1 456 26.9 2 445 23.8 3 451 25.4 4 447 23.8 5 452 27.0 Back 1 443 23.5 2 450 26.8 3 454 25.0 4 452 29.0 5 453 24.7

a c

b d

Figure 6 Testing of bulletproof vest from bullet impact: (a) clamping the vest with modeling clay; (b) indentation of modeling clay after the bullet impact on the vest (front size); (c) bullet blocked in the front size of the vest and (d) bullet blocked in the back size of the vest.

J.Met.Mater.Miner.26 (2) 2016, DOI:10.14456/jmmm.2016.7

26 UDON, S. et al

The result showed that it appeared a small 4. Chen, Y.L. Chu, C.K., Chuang, W.Y., Lee, indentation in the range from 23.5 to 29.0 mm on S.H. and Lee, K.C. (2007). 16 th the surface of the modeling clay as shown in International Conference on Figure 6 (b). From the National Institute of Justic Composite Materials. Kyoto, : 1-7. (NIJ) (U.S Department of Justice)(2), the indentation of the modeling clay should not 5. Dimeski, D., Bogoeva-Gaceva, G. and exceeded 44 mm in the quality testing of the Srebrenkoska, V. (2011). Ballistic bulletproof vest. The damage of the fabric in the properties of polyethylene composites vest was not much, also, the bullet was blocked in based on bidirectional and unidirectional the fabric as shown in Figure 6 (c-d). Hence, this Fibers . Zbornik radova result indicated that the plain weave of the aramid Technoloskog fakultela u Leskovcu. 20: fabric had the performance to resist the bullet. 184-191. Chu and Chen reported that the plain weave construction had a high density of warp-weft 6. Bernetic, J., Vuherer, T., Marcetic, M. and interweaves(11). This caused the fabric resisted the Vuruna, M. (2012). Experimental impact. However, the weight of the bulletproof research on new grade of steel vest should be reduced for the comfortable to protective material for light armored wear. vehicles. J Mechanical Eng. 58: 416- 421. Conclusion The plain weave construction of the 7. Gopinath,G., Zheng, J.Q., and Batra, R.C. aramid fabric was designed to produce the (2012). Effect of matrix on ballistic bulletproof vest. The resistance of the aramid performance of soft . fabric from the bullet impact depended on the Comp. Structure. 94: 2690-2696. layers of the fabric, impact velocity and type of bullet. The bulletproof vest consisted of the 32 8. Mahbub, R.F., Ratnapandian, S., Wang, L. and layers of plain weave aramid fabric had the Arnold, L. (2013). Evaluation of comfort performance to resist with the .44 magnum. properties of coated Kevlar/wool ballistic fabric. Adv. Mater. Res. 821-822: 342- 347. Acknowledgement This research is supported by a grant from the 9. Regassa, Y., Likeleh, G., and Uppala, R. Rajamangala University of Technology (2014). Modelling and simulation of Krungthep. bullet resistant composite body armor. Inter. J. Res. Studies and Sci. 1: 39-44.

References 10. Hatch, K.L. Textile Science. New York: West Publishing, 1993.

1. Bajaj, P. and Sriram, S. (1997). Ballistic 11. Chu, C.K. and Chen, Y.L., and Uppala, R. protection clothing: An overview. Indian (2010). Ballistic-proof effects of various J of Fibre&Textile Res. 22 woven contruction. Fibres and Textiles. (December): 274-291. 18: 63-67.

2. National Institute of Justice NIJ Standard-

0101.06. (2008). Ballistic resistance of body armor. U.S. Department of Justice, Washington, D.C.

3. Lee, Y, Wetzel, E.D. and Wagner, N.J. (2003). The ballistic impact characteristics of Kevlar woven fabrics impregnated with a colloidal shear thickening fluid. J. Mater. Sci. 38: 2825-2833.

J.Met.Mater.Miner. 26 (2) 2016, DOI:10.14456/jmmm.2016.7